1. FIELD OF THE INVENTION
This invention relates in general to hydraulic couplings, and specifically to hydraulic couplings used in undersea drilling and production applications. More particularly, this invention involves a hydraulic coupling configured to urge the members together and axially compress a ring-shaped seal in the female member upon connection of the members.
2. DESCRIPTION OF THE RELATED ART
Subsea hydraulic couplings are old in the art. The couplings generally consist of a male member and a female member with sealed fluid passageways connected therebetween. The female member generally is a cylindrical body with a relatively large diameter longitudinal bore at one end and a relatively small diameter longitudinal bore at the other. The small bore facilitates connections to hydraulic lines, while the large bore seals and slidingly engages the male member of the coupling. The male member includes a cylindrical portion at one end having an outer diameter approximately equal to the diameter of the large bore of the female member of the coupling. The male member also includes a connection at its other end to facilitate connection to hydraulic lines. When the cylindrical portion of the male member is inserted into the large bore of the female member, according to various embodiments of the device, fluid flow is established between the male and female members.
In the past, various types of seals have been used between the male and female members of the coupling. For example, U.S. Pat. No. 4,694,859 discloses an undersea hydraulic coupling with a hollow, ring-shaped metal seal that is pressure energized to seal radially between the female member and the outer surface of the male member. Similarly, in U.S. Pat. No. 4,754,470 two metal seals are positioned between the circumference of the male member and central bore of the female member.
Another type of seal in an undersea hydraulic coupling is disclosed in U.S. Pat. No. 4,637,470. This patent shows a seal that is V-shaped in cross section and is compressed axially between the end or leading face of the male member and a shoulder in the bore of the female member. Belleville washers are used to provide a force between the members to maintain the seals in tight contact. This force is necessary to avoid leakage of hydraulic fluid if the members are slightly separated.
During use of hydraulic couplings, fluid pressure is exerted between the male and female members in such a way as to tend to separate them. The male and female members are typically attached to opposing manifold plates which are held together by bolts or hydraulic members attached to the plates. The male members are commonly attached to one plate while the female members are attached to an opposing plate so as to face the male members and align with them. Typically, groups of 10 or more coupling members are attached to each manifold plate. The manifold plates tend to warp or rock when coupling members are pressured up, thus causing the coupling members to separate slightly.
In the prior art, various approaches have been suggested to secure the male and female members of the coupling together. For example, lock sleeves have been used in so-called quick release couplings. In those type of couplings, a sleeve is pulled back from one member of the coupling to lock or release the coupling members together. Typically a ball and groove configuration is used.
Another approach, as disclosed in U.S. Pat. No. 4,637,470, uses Belleville washers to provide a force urging the numbers together.
Still another approach is that of U.S. Pat. No. 4,915,419 to Robert E. Smith III. This patent shows an apparatus for locking together simultaneously one or more male and female coupling members using a sliding lock plate. In the locked position, passages in the lock plate are configured to engage the circumference of the male and female coupling members and restrict axial movement of the members.